Machine for graining planographic plates



W. H. LONG.

MACHINE FOR GRAINING PLANOGRAPHIC PLATES.

APPLICATION FILED MAR. 5, 1918.

Patented Mar. 29, 1921.

3 SHEETSSHEET 1.

JNVENTOR ATT" RNEY NORRIS PETERS. lNC., LITNO WAsmNcwN D C w. H. LONG.

MACHINE'FOR GRMNING PLANOGRAPHIG' PLATES.

APPLICATION FILED MAR 5, 1918. 1,373,140. Patented Mar. 29,1921.

3 SHEETS-SHEET 2.

Pzitented Mar. 29,1921.

3 SHEETS-SHEET 3- APPLICATION FILED MAR. 5. 1918.

. H. LONG.

MACHINE F0 R GRAINING PLANOGRAPHIC PLATES.

INVENTOE m ATTORNEY NORRS PETERS lNC.. LITHOu. WASHINGTON. D. C

UNITED STATES PATENT OFFICE.

WILLIAM H. LONG, 01? NEW YORK, N. Y.

Application filed March 5, 1918.

To cZZ whom it may concern:

Be it known that 1, WILLIAM H. Lone, a citizen of the United States, and a resident of New York, in the county of New York and vState of New York, have invented certain new and useful Improvements in Machines for Graining Planographic Plates, of which the following is a specification.

The invention relates to machines for graining the surface of metallic plates, such as flexible plates of zinc or aluminum, preparatory to using such plates as planographic printing plates.

Objects and advantages of the invention will be set forth in part hereinafter, and in part will be obvious herefrom, or may be learned by practice with the invention; the same being attained through the instrumentalities and combinations pointed out in the appended claims.

The invention consists in the novel parts, constructions, arrangements, combinations and improvements herein shown and described.

The accompanying drawings referred to herein and constituting a part hereof, illustrate one embodiment of the invention, and together with the description serve to explain the principles thereof.

Of the drawings:

Figure 1 is a side elevation, with parts 1n section and with parts broken away, of a plate grainer embodying the invent1on;

Fig. 2 is an elevation looking at Flg. 1 from the left;

Fig. 3 is a top plan of the machine; and

Fig. 4; is a fragmentary section of the mounting for the plate box upon the 08011- lating frame.

1n the work of preparing metal plates, such as zinc or aluminum plates for use as planographie printing plates, it is usual to prepare the surface of such plates for rece1ving the planographic printing design by graining the plates, which consists in minutely cavitating the entire surface of the plate. The success of the printing depends very largely upon securing a proper and uniform graining of the surface of the plate, it being essential for first-class work that the grain be of a particular texture or quality and that it beuniformly of such texture or quality over the entire surfaceof the plate. In graining the plate, it is customary to place upon the surface of the plate suitable abrading materials, in the case of zinc plates,

Specification of Letters Patent.

Patented Mar. 29, 1921.

Serial No. 220,548.

a quality of silex and a layer of glass or clay marbles being used, and in the case of alunnnum plates, pumice being substituted for the silex and some times wooden balls for the marbles, on account of the softer texture of the aluminum. The plate support and plate are given movement which, through the inertia of the abrading materials, produces relative movement between such materials and the plate, thereby effect ing the graining.

The present invention is directed to a machine for producing an improved and highly efficacious motion for the abrading materlals, such as will produce a grain of the proper character and uniform in character over the entire plate. The invention is further directed toward producing a simple and efficient machine, and one having such movement that the direction and change of direction thereof will not be such as to rack and jar both the machine and the floor and building where it is installed.

Referring more particularly to specific features of the invention, and in carrying out the various objects already outlined, a plate support is provided which is oscillated to and fro, and which has imparted thereto simultaneously a rotary movement, which latter is preferably intermittent or step by step. Referring to the illustrated construction, a supporting frame is provided having uprights 1 and 2, and one or more cross frames 3. In the upper part of said frame are provided journals 4 and 5, and rockingly supported thereon are trunnions 6 and 7. The trunnions 6 and 7 are fixed to a rocker frame 8, which frame thus rocks vertically upon the two trunnion bearings.

The plate box or holder 15 is pivotally supported centrally of the rocker frame '8, the bearing being shown as a pin 16 projecting downwardly from the bottom 17 of the plate holder. The pin 16 projects through an aperture 18 in the rocker frame, and suitable securing means may be provided, such as a pin 19 through the pin 16.

Suitable supports are provided upon which the plate holder may rotate, and as embodied two rollers 20 and 21 are journaled, respectively, in opposite ends of the rocker frame, and rollers 22 and 23 are journaled in the frame members 1 and 2, thus providingsupporting rollers under the plate holder substantially a quadrant apart. A circular track 14: is preferably provided on the bottom of the plate holder, the track bearing on the rollers. All of the rollers are in supporting position with respect to the plate holder at all points in its oscillation, as the rollers in the stationary frame are substantially in the line about which the plate holder rocks or oscillates.

The embodied form of oscillating means comprises a wrist-pin 2% fixed to the rocker frame 8, to which wrist-pin is pivotally connected a pitman 26. The other end of the pitman is pivotally connected to a wrist-pin 27 which is fixed on a crank disk or wheel 28. Crank disk 28 is jeurnaled at 29 on the machine frame. The crank disk 28 is shown as a belt pulley, to provide a suitable drive, although other forms of driving means may be used if desired.

The embodied form of means for effecting the intermittent rotary motion of the plate holder comprises an annular ratchet fixed to the bottom 17 of the plate holder, and cooperating therewith is a pawl pivot-ally supported on the machine frame. The pawl is preferably provided with a fixed pivot point 34. The tail of the pawl is acted upon by a spring 35, connected thereto and to the frame 1. As the plate holder is rocked or oscillated upwardly on that side of its pivotal bearing where the pawl engages the ratchet, the pawl will slip backwardly along the ratchet but will be held to the ratchet by spring 35, and as the plate holder rocks in the opposite direction the pawl will impart rotatory motion to the plate holder. This motion may be varied in its extent by using interchangeable pawls of diiferent lengths, by changing the pivot point of the pawl, or otherwise as desired.

In accordance with one feature of the invention, the plate holder is interiorly shaped to cooperate with the movement of the plate holder, to preserve the continuity and integrity of the layer of marbles, and to control the movement thereof to produce the character of grain desired. As embodied, the central part 17 of the plate holder is flat and substantially of the outline of th usual rectangular zinc or aluminum plate, the plate being fastened thereto before the abradents are placed thereon. The circumj acent portions 37 of the plate bottom are inclined upwardly from near the margins of the plate and outwardly to the side walls 38 of the plate holder. The side walls 38 of the plate holder are preferably cut off at the corners 39 to save space, and one of the side walls 38 or 39 is formed wholly or partly into a gate, through which the abradent materials and'slush may be dumped out and the finished plate washed clean before removal.

By reason of the shape of the bottom of the plate holder, the movement of the marbles is gradually and cumulatively checked and the marbles are ureserved in a layer and do not roll ofi' the plate and pile up at the edges of the box, but on the contrary the layer is preserved intact and is given the desired relative movement over the surface of the plate.

The invention in its broader aspects is not limited to the exact details shown and described, nor to any particular details, but changes may be made therein, without departing from the principles of the invention. and without sacrificing its chief advantages.

1 claim:

1. A machine for graining planographic plates including in combination a centrally pivoted plate holder, a support therefor. means for cilecting rotary motion thercbetween including a pawl on one and a ratchet on the other and including a device for imparting additional, motion to the plate holder.

2. A machine for graining planographic plates including in combination a centrally pivoted plate holder, a support therefor, means for effecting rotary motion therebetween including a pawl on one and a ratchet on the other, and means for rocking the holder.

3. A machine for graining planographic plates including in combination a centrally pivoted plate holder, a support therefor, means for effecting rotary motion therebetween including a fixed pivot pawl on one and a ratchet on the other, and means for rocking the holder to effect a rotary feed between the pawl and ratchet.

4.. A. machine for graining planographic plates including in combination a centrally vertically pivoted plate holder, a support therefor, means for effecting rotary motion therebetween including a pawl on one and a ratchet on the other and including a device for imparting relative vertical rocking movement between the pawl and ratchet.

5. A machine for graining planographie plates including in combination a centrally vertically pivoted plate holder, a support therefor, means for effecting rotary motion therebetween including a pawl on one and a ratchet on the other, and means for rocking the holder and one of the cooperating pawl and ratchet members.

6. A machine for graining planographic plates including in combination a centrally pivoted plate holder, a support therefor, means for effecting rotary motion therebetween including a fixed pivot pawl on one and a circular ratchet on the other and devices for effecting rocking vertical relative movement between the pawl and ratchet.

7. A machine for graining planographic plates including in combination a centrally pivoted plate holder, a support therefor,

lll)

means for effecting rotary motion therebetween including a pawl on one and a circular ratchet on the other, and means for rocking the holder.

8. A machine for graining planographic plates including in combination a centrally vertically pivoted plate holder, a support therefor, means for effecting rotary motion therebetween including a pawl on one and a circular ratchet on the other, and means for rocking the holder and the pawl and ratchet relatively to each other.

9. A machine for graining planographic plates including in combination a vertically and horizontally pivoted plate holder, means for rocking the holder about its horizontal pivot and means including a pawl and ratchet for rotating it about its vertical pivot.

10. A machine for graining planographic plates including in combination a vertically and horizontally pivoted plate holder, means for rocking the holder about its horizontal pivot and means includin a pawl and circular ratchet for rotating it about its vertical pivot.

11. A machine for graining planographic plates including in combination a vertically and horizontally pivoted plate holder, means for rocking the holder about its horizontal pivot, and means for imparting intermittent feeds to it about its vertical pivot.

12. A machine for graining planographic plates including in combination a plate holder, a cross member on which the holder is vertically pivoted, a support on which the cross member is horizontally pivoted, means for vertically rocking said cross member, a circular ratchet on the plate holder, and a fixed pivot pawl mounted on said support.

In testimony whereof, I have signed my name to this specification, in the presence of a subscribing witness.

WILLIAM H. LONG.

Witness:

J OHN D. MORGAN. 

